Studied by 1 person
Dr. Emanuelle Charpentier
Funding and acting director of the Max Planck Unit at Humboldt University in Berlin, Germany
Microbiologist & Geneticist
Worked with Dr. Jennifer Doudna to decode CRISPR/CAS9 System in bacteria
2020 Nobel Prize in Chemistry
Scientific theories are…
an explanation for a general class of phenomena supported by a wide body of evidence.
The three theories that are the framework for biology are:
the theory of evolution by natural selection
cell theory
chromosome theory of inheritance
Life is…
cellular.
Robert Hooke:
1665→ created the first microscope (30x magnification)
Anton Von Leeuwenhoek:
around 1665→ developed a microscope with 300x magnification and observed the first single-celled organism
What is a cell?
a highly organized compartment
separated from their environment by membrane barrier
The cell theory states…
all organisms are made up of cells and all cells come from pre-existing cells.
Theodore Schwann→
→ Animals are made of cells
Matthias Jakob Schleiden→
→ Plants are made of cells
Rudolf Virchow* (might have plagiarized R. Remak)→
→ Cells come from pre-existing cells
Spontaneous generation proposed that…
organism arise spontaneously.
Louis Pasteur (1822-1895)…
put the spontaneous generation vs. cell theory concepts to the test in the 1800’s.
Pasteur’s results supported…
the cell theory because through his experiment, we know that cells do not spontaneously arise (straight-necked flask and swan-necked flask experiment)
Carbon (C), Hydrogen (H), Nitrogen (N), Oxygen (O), Phosphorous (P), and Sulfur (S) make up ___% of living cells.
99%
Covalent bonds…
share electrons.
The most electronegative molecule is…
oxygen (O).
In non-polar covalent bonds…
electrons are shared equally.
In polar covalent bonds…
electrons are not shared equally.
Solution
A solute dissolved in a solvent
The best solvent is…
Water.
Properties of water:
excellent solvent
small size, bent shape, highly polar
hydrogen bonds (which are cohesive)
density (can change from a solid to a liquid and to a gas)
high specific heat
Hydrophobic
“water fearing” (non-polar)
Hydrophilic
“water loving” (ions, polar molecules)
Biological significance of pH:
water breaks down into H+ and OH-
acids give up H+ and increases protons in solution
bases acquire H+ and decreases protons in solution
pH effects biological function
pH (“power of hydrogen”)…
logarithmic
one unit of pH represents change in H+ equal to a factor of 10
Energy
the capacity to do work or supply heat
Potential energy
stored energy (related to electron positioning)
Kinetic energy
motion (thermal)
First Law of Thermodynamics
energy is conserved and cannot be created or destroyed. it can be transferred or transformed.
Entropy
the amount of disorder in a molecule.
Reactions are…
spontaneous if they proceed on their own and no energy is needed.
Processes proceed in the direction that results in…
potential energy of products less than reactants.
Thermodynamics drive…
biological processes.
Life is…
carbon (C) based.
Carbon (C) is found in…
nearly all molecules in organisms.
Organic compounds contain carbon
limitless variety of shapes
different combination of single and double electron bonds
Carbon (C) provides a…
“molecular skeleton”
Polymerization
small molecules (monomers) can join together into bigger molecules (polymers) via polymerization.
Monomers polymerize via…
condensation reactions.
reverse reaction is called hydrolysis (water in, monomer out)
Macromolecules of life form via…
polymerization.
Proteins are…
the most abundant and versatile macromolecules.
Amino acids are…
the building blocks of proteins.
What happens to amino acids in water?
they ionize.
How many amino acids are there with unique side chains?
20
Side chains
may contain functional groups
affect solubility
Proteins are formed by…
peptide bonds.
Nucleic acids
store the info of life
polymer of nucleotide monomers
nucleotides consists of a sugar, phosphate group, and a nitrogenous base
Ribonucleotides are…
monomers of RNA.
Deoxyribonucleotides are…
monomers of DNA
DNA
A→T
C→G
RNA
A→U
C→G
Carbohydrates are important in…
cell structure, identity, and energy storage.
Carbohydrates are composed of…
sugar
monosaccarides → 1 sugar
differ in arrangement and number of carbons
Polysaccharides are…
polymers of monosaccharides
condensation reaction between hydroxyl (glycosidic linkage)
energy storage: starch (plants) & glycogen (animals)
Structural: cellulose (plants), chitin (fungi, insects, and crustaceans), & peptidoglycan (bacteria)
Lipids are…
hydrophilic, e- containing compounds
contain hydrocarbons
Hydrocarbons are…
Non-polar molecules with only carbon and hydrogen
saturated=only single bonds
unsaturated=1+ double bonds (kinks)
Building blocks of the plasma membrane
The major group of lipids are…
steroids
fats
phospholipids
Steroids
bulky, four ring structure
cholesterol, estrogen
Fats
3 fatty acids linked to glycerol
energy storage
Phospholipids
glycerol linked to phosphate and two hydrocarbon chains
Phospholipid bilayer
amphipathic
hydrophobic interactions
form spontaneously
more stable in a cluster
plasma membrane = life's defining barrier
Selective permeability
small, non-charged, move easily
large, charged cross slowly, if at all
Other factors: length of tail (short > long), saturation stage (unsaturated>saturated), presence of cholesterol decreases permeability, temperature (slow=cold, fast=warm)
